1. Field of the Invention
The present invention relates generally to the field of production and formulation of pharmaceuticals. More specifically, the present invention relates to a novel pharmaceutical formulation of a combination of topical anesthetics.
2. Description of the Related Art
Topical anesthetic compositions are generally well known. For example, U.S. Pat. No. 2,004,891 to Goldberg teaches an anesthetic solution containing procaine acetate and epinephrine HCl. U.S. Pat. No. 3,038,835 to Endres et al. discloses derivatives of 2,6-xylidine as a surface anesthetic. Similarly, RESOLVE.TM. is a commercially available product that produces surface anesthesia when applied topically to inflamed or abraded skin or to mucous membranes.
Topical anesthetic compositions such as tetracaine-adrenaline-cocaine are considered safe and effective. It has been considered beneficial in the art to have a more viscous topical preparation that could be directly applied onto the wound surface so as to be able to use a minimal volume and dosage of the pharmaceuticals and to remain in contact with the lacerated tissue of interest without running off onto mucosal or ocular surfaces.
There are several known disadvantages associated with the application of conventional topical anesthetic medications. For example, the medicine must be applied to and saturate a cotton ball or similar applicator which tends to absorb most of the medicine. This drawback has prompted the use of a much larger volume of medication which necessarily increases the cost of a unit dose of medication and possible over-exposure to certain components, e.g., cocaine. In addition, the medication-saturated applicator may not remain in direct contact with the entire wound surface leading to inadequate areas of anesthesia. Furthermore, it may be difficult to secure an applicator to certain body areas, such as a head wound and a mainly liquid topical anesthetic could easily run off the applicator and irritate ocular or mucosal surfaces.
Bonadio and Wagner (Annals of Emergency Medicine, 21:1435-1438, December 1992) describe an adrenalin-cocaine gel topical anesthetic for children. Unfortunately, the topical anesthetic composition of Bonadio and Wagner was not sterile. The prior art is deficient in the lack of sterile topical anesthetic gel formulation which has superior properties and actions. The present invention fulfills this longstanding need and desire in the art.